Mitoulas LR et al Br J Nutr. 2002 Jul;88(1):29-37.
Variation in fat, lactose and protein in human milk over 24 h and 
throughout the first year of lactation.

This is just one of the articles from Peter Hartmann's lab in Western 
Australia on the topic, but Peter started teaching this in the mid to 
late 90's when he became a popular speaker in America too. The REAL take 
home message is that the fat content of milk increases as the breast 
empties. Put that together with other research that shows it is 
sufficient milk *volume* that is important to infant growth, and it 
means that foremilk and hindmilk don't really matter much for your 
average baby. It's kind of misleading to say they don't exist at all, 
but it's hard not to oversimplify when you try to distill all our 
knowledge of lactation science and management to a brief course.

What Peter was saying is that fat content of milk varies between women, 
varies between feeds, and varies based on the time from the last feed 
(which Woolridge knew as well, and based his hypothesis about too much 
foremilk causing failure to thrive one). But within a single woman, 
there will be higher fat in her milk as her breast empties. Both men 
recommended increasing infant self-regulation (let the baby decide which 
breast to take, how long to take it, and whether to take the other), 
which led to the demise of the 'ten minutes on each side' rules of the 
1970s (which stemmed themselves from an over-application of a small 
study Woolridge and Lucas published in Lancet of how long it took for 
six 6 day old babies to 'empty' the breast, before we knew about 
multiple milk ejections in a feeding and that babies got more efficient 
in sucking as they got older, and that moms milk production increased 
exponentially in the early days of lactation).
The human race has a poor record of understanding a process before 
intervening in it. My personal recommendation is that we strive to 
understand how bf/lactation naturally works before we go around making 
rules that might mess it up.
<http://www.ncbi.nlm.nih.gov/pubmed?term=%22Hartmann%20PE%22%5BAuthor%5D>

Catherine Watson Genna BS, IBCLC  NYC  cwgenna.com


On 2/21/2011 8:48 AM, Tina Carlson wrote:
> Just an FYI on the "foremilk vs hindmilk does not exist":    This is being taught to students in the CLC class from Healthy Children's Center for Breastfeeding. I took the class in Aug 2009, taught by Karin Cadwell and Lois Arnold.  They were excited to tell us of brand new research that had just been published showing that the "hindmilk" (creamier, higher-fat breastmilk) does not necessarily come at the END of the feeding, but may also come closer to the beginning of the feed and/or in the middle.  They said that in light of that new research, the terms "hindmilk" and "foremilk" now only apply to the point of time in the feeding.
>
> Unfortunately, they did not reference the study in our notebooks (maybe a more recent copy of their notes would have it) and I have never been able to find a copy of that research myself (maybe someone with subscriptions to pay-to-view journals could find it).
>
> So.. now you know where the students are getting the idea.
>
> Also.. milk from a cow also does not come out homogenized.  It is the milk processing plant that does that.  :)
>
> Tina Carlson, PPD, CLC
> IBCLC Exam Hopeful 2011
>
>
>
>
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